Investment Securities Available for Sale (Details 2) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Market Value	$ 342,577	$ 346,043
U.S. Government securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	0
1 Year up to 5 Years	33,886
More than 5 Years	0
Market Value	33,886
Corporate securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	6,685
1 Year up to 5 Years	44,840
More than 5 Years	412
Market Value	51,937
U.S. mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	839
1 Year up to 5 Years	5,751
More than 5 Years	167
Market Value	6,757
Commercial mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	5,084
1 Year up to 5 Years	4,614
More than 5 Years	6,060
Market Value	15,758
U.S. asset backed securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	2,080
1 Year up to 5 Years	9,852
More than 5 Years	1,461
Market Value	13,393
Index-linked U.S. bonds
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	0
1 Year up to 5 Years	2,131
More than 5 Years	0
Market Value	2,131
Marketable debt securities
Schedule of Available-for-sale Securities [Line Items]
Under 1 Year	14,688
1 Year up to 5 Years	101,074
More than 5 Years	8,100
Market Value	$ 123,862